2011-03-14

Opportunity Sol 760 (Spirit Sol 780)

It's a memorable day for me because it's my first day back on Opportunity since she hurt her arm back around Thanksgiving. SOWG chair Wendy Calvin sees another reason to celebrate. "Today's a banner day," she says. "Because today we start our two-kilometer-plus trek to Victoria Crater. Larry has suggested a namespace for us to use for a while -- cattle trails, and famous cowboys and cowgirls." Only the good kind, she hastens to add -- not Jesse James.

With uncharacteristically impeccable timing, I've missed all the boring stuff. The agonizing IDD troubles, the slog past Payson Crater -- all in the past. Yesterday they climbed out of Payson, and today we drive.

We'd like to jump straight to a gallop, but Cooper points out that this is our first longish drive with a post-drive unstow. So we play it conservatively, holding ourselves to a 30m drive (even though this means giving back drive time, which kills me).

But while everyone upstairs is happy to be on the trail, there's very bad news from our other faithful steed. She threw a shoe. That is, Spirit made it through the drive just fine, but at the end, during the turn for comm, the right front drive actuator saw a weird current spike. The current draw went from a nominal 0.6 amps way up to 1.5 amps, then, bizarrely, fell into negative territory -- as if it were feeding power back into the system -- went back to positive territory, and flatlined. Then she declared a motion error and stopped turning. So we have a broken vehicle, but since we didn't get our turn for comm, our available data is limited.

I get a chance to quiz Jeff Biesiadecki about this, and he's more than usually doleful. The odds are that Spirit finally blew out her right front drive motor. It's not likely to be a potato caught in the wheel (though we can't be sure, since the poor downlink kept us from getting our front HAZCAM images), since that should have caused the current to spike to 2 amps and stay there until it stalled. Worse yet, with winter creeping up, we can't sit here for a week and diagnose the problem.

We won't know much more until tomorrow, when more data comes down. But the likely scenario is that Spirit has just gone from being essentially healthy but power-starved, to damaged and power-starved -- and damaged in a way that may keep us from getting to the relatively power-rich area we need to get to.